Foil laminates and various intermediate assemblies are currently used in a number of applications, ranging from containers for microwave packages to smart cards. Such laminates have regularly been created by die cutting, stamping and other mechanical processes that generally lend themselves well to high speed situations in which a relatively simple shape or pattern can be created.
The increased demand for circuits has created a need for a manufacturing method that can quickly and efficiently produce such circuits. One such method is disclosed in U.S. Patent Application No. 2007/0171129 A1. This method includes the steps of, first, providing a reinforced metal foil laminate having a metal foil layer bonded to a reinforcement layer, and a carrier layer bonded to the metal foil laminate. The method includes the step of using a rotary die cutter to cut an antenna pattern through the metal foil laminate to the carrier layer. The method concludes with the step of removing an undesired matrix portion of the reinforced metal foil laminate to provide a metal foil laminate antenna disposed on the carrier layer.
Use of a rotary die cutter to cut a circuit pattern can be advantageous because rotary die cutting is both fast and inexpensive. However, rotary die cutters have poor resolution, and are limited to having a minimum distance between cut lines of 1 mm. An additional problem with using a rotary die cutter to cut a circuit or other construction requiring high precision is that the cylindrical die used by the rotary die cutter cannot be quickly or easily changed. Accordingly, the circuit design is not readily changeable, and thus it is often not economically feasible to produce small batches of a particular circuit design due to the need to constantly change out die heads. Furthermore, any change in a circuit design would require a large lead-time, as a new cylindrical die must be manufactured each time the circuit design is changed. Having a large number of designs can lead to a large inventory of die heads, the storage of which can occupy valuable factory floor space.
Conventional stamping techniques also suffer from similar drawbacks, in that the stamping die cannot be readily changed for a new design and stamping dies may not generally be able to produce designs having very slight tolerances. An example of stamping foils is shown by US 2002/0018880. Publications, patents and patent applications are referred to throughout this disclosure. All references cited herein are hereby incorporated by reference.
What is needed therefore is an improved method of manufacturing small batches of intricate structures that can be used for a variety of purposes without suffering from the foregoing drawbacks.